Ventilation system for electronic equipment

ABSTRACT

A system for ventilating an enclosure for electronic equipment has an axial fan mounted between first and second pipes. The first and second pipes have major and minor diameters, the diameters being sized to fit into different sized of standard ventilation duct. The first and second pipes, the fan, mounting means, and an optional gas cap can be assembled to provide airflow through the system in either of two directions. The system if preferably connected by ducting to an enclosure having heat-generating electronic components and mounted some distance away therefrom, such as in an attic space.

FIELD OF THE INVENTION

[0001] The present invention relates to a ventilation system for increasing the flow of heated air from an enclosure for electronic equipment.

BACKGROUND OF INVENTION

[0002] The reliability of all electronic devices is influenced by their operating temperatures. If the electronic device is operated below a certain temperature, it will not function properly. If the electronic device is operated above a certain temperature, it will fail prematurely. The temperature at which such failure occurs decreases with time as the device is aged by operational stresses. If the device can be operated below all critical temperatures, voltages and currents, then it should be able to operate indefinitely. The higher the device is operated above these critical levels, the sooner the device will fail.

[0003] Several methods have been employed to reduce the operational temperatures of electronic devices. The device may incorporate heat sinks to enhance the ability of the device to dissipate heat. A number of devices may be arranged in a manner in which the generated heat establishes natural convection currents which may be employed to draw in cool air at the base of the enclosure and to exhaust warmer air above. The device may be placed in an actively ventilated enclosure wherein an air moving device is employed to either pump ambient air into or draw heated air out of the enclosure. The device may be actively cooled by refrigeration equipment to reduce the operational temperature below the otherwise available ambient temperature. These methods can be and are employed in various combinations.

[0004] In industrial environments, electronic device failure can be very costly due to line stoppage. Reliability of the electronic device is of prime importance. The noise generated by increased ventilation is minimal with respect to that generated by common industrial operations. Thus, industrial electronic devices are often highly ventilated.

[0005] In office environments, thermal stresses are not as prevalent as in industrial environments. However, noise reduction is a major concern. A noisy device will not be purchased if there is a quieter alternative available. Competition motivates manufacturers to provide quiet devices wherein the minimal amount of ventilation required for the typical environment is employed.

[0006] The means conventionally used to reduce the noise generated by ventilation involve the reduction of ventilation capacity. Low speed fans generate less noise but inherently less flow. Fans are usually placed internally to isolate the noise. With such placement, there is likely to be an internal recirculation component reducing the effective fresh air exchange. Exhaust ports are placed at the rear of the enclosure to limit forward propagation of noise. Little attention is paid to the noise generation characteristics of the air mover, because air movers are standardized components. The manufacturers of these air movers have made some progress in terms of airfoil design and turbulence minimization to reduce the generated noise. However, electronic device manufacturers simply add these air movers to their devices without modification. The interface between the air movers and their surroundings has been largely ignored.

[0007] The advent of the home theater and its associated heat-generating electronics has combined the requirement of the industrial environment for high air flow with the office requirement of low noise. Home theater systems comprise video, audio and control components and may generate heat from hundreds to thousands of watts. Such systems are also expensive, and premature failure cannot be tolerated.

[0008] In the preferred embodiment, the invention is directed to solving the conflicting problems of adequate airflow and low noise, particularly in noise-sensitive environments, such as the home. The present invention includes a fan mounted to air-flow pipes so as to accept at least two different sizes of ventilation duct. The duct may be connected to the enclosure containing the electronic equipment, and the fan may be mounted in an attic, false ceiling, crawl space, or through a roof, thus removing the source of noise from the home theater or other noise-sensitive area.

SUMMARY OF THE INVENTION

[0009] The invention is embodied in a ventilation system comprising components which may be provided to the user pre-assembled, or in kit form.

[0010] The preferred embodiment comprises a first pipe that has a first end and a second end; the first end of the first pipe has a major diameter and the second end of the first pipe has a minor diameter. The major and minor diameters of the first pipe are sized to fit the inside diameters of standard ventilation ducts.

[0011] An axial fan, preferably driven by a brushless motor, provides airflow through the system. The axial fan is connected to the first pipe at its first end. A first mounting means is provided for connecting the first end of the first pipe to the axial fan.

[0012] Further, there is a second pipe that the second pipe having a first end and a second end; the first end of the second pipe has a major diameter and the second end of the second pipe has a minor diameter. Again, the major and minor diameters of the second pipe are sized to fit the inside diameters of standard ventilation ducts. A second mounting means connects the first end of the second pipe to the axial fan, so that operation of the fan causes airflow through the first and second pipes.

DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 depicts the elements of the preferred embodiment before assembly.

[0014]FIG. 2 depicts the assembled preferred embodiment.

[0015]FIG. 3 is a top view of the assembled preferred embodiment.

[0016]FIG. 4 depicts another embodiment of the invention.

DETAILED DESCRIPTION

[0017]FIG. 1 depicts the elements of the preferred embodiment before assembly. Generally, an axial fan (100) is mounted between two airflow pipes (110, 140). The axial fan (100) would typically be an AC brushless-motor type, typically having an air delivery of about 240 cubic feet per minute, although greater or lesser capacities could be used.

[0018] A first pipe (110) has a major diameter (130) at its first end, and a minor diameter (120) at its second end. The major diameter (130) would typically be sized to fit inside standard 6-inch ventilation duct. The minor diameter (120) would typically be sized to fit inside standard 5-inch ventilation duct. In the preferred embodiment, the first pipe (110) and the second pipe (140) are made of noise-absorbing PVC plastic, although ABF plastic could be used, at the cost of higher emitted noise. Metal pipes could be used at greater cost and additional weight. The first pipe (110) is connected to the axial fan (100) with a first mounting means (160). In FIGS. 1 and 2, the mounting means is a PVC ring having axial holes (180) for screw mounting to the axial fan (100), and radial holes (190) for screw mounting to the first pipe (110). Of course other mounting means are possible, including threaded holes or inserts for receiving machine screws, glue, or threaded engagement with the first pipe (110). The mounting means (160) is preferably a ring cut from PVC pipe, but could be made of other plastics or metal. Also, it would be possible to use a pipe flanged at the major diameter (130) for the first pipe (110), thereby allowing screw or other connections directly between the axial fan (100) and the first pipe (110). Preferably, such a flange would be integral to the pipe. A depiction of a first pipe (110) having a flange (165) is shown in FIG. 4. In a still further embodiment, the mounting means (160) may be a ring having a flange, and this flange may be connected to the first pipe (110) and axial fan (100) by any of the several ways just described.

[0019] Similarly, a second pipe (140) is provided. The second pipe (140) may have a major diameter (130) and a minor diameter (120) also sized to fit inside standard ventilation duct. The second pipe may also be connected to the axial fan (100) by a second mounting means (170) as described above for the first mounting means (160).

[0020] The reader should recognize that only one pipe need be sized to receive different sized ducts, because the other pipe, if the exhaust pipe, may not have duct connected to it, but rather be open to an attic space or mounted through a roof.

[0021] A gas cap (150) may be mounted over the minor diameter (120) of the second pipe (140), to keep dust, rain, or insects from entering the duct system.

[0022]FIG. 2 depicts the preferred embodiment assembled. It should be apparent that the preferred embodiment may be provided to the user un-assembled, as a kit for construction of a ventilation system. In that case, the user may choose which end of the system will be the inlet and which will be the outlet, as well as what size of duct will connect with the unit, even what capacity of fan will be used. If the unit is mounted horizontally, or further connected to a ventilation duct at its exhaust, a gas cap (150) will not be necessary. When assembled, the system will typically be mounted to a rafter or joist with a pair of conventional zip ties.

[0023]FIG. 3 is a top view, with the gas cap (150) removed, looking into the second end, or minor diameter (120) of the second pipe (140). FIG. 3 shows the axial fan (100) and its motor (200) and blades (210). 

I claim:
 1. A ventilation system comprising: a first pipe; the first pipe having a first end and a second end; the first end of the first pipe having a major diameter and the second end of the first pipe having a minor diameter; an axial fan; the axial fan connected to the first pipe at its first end; a second pipe; the second pipe having a first end and a second end; the first end of the second pipe having a major diameter and the second end of the second pipe having a minor diameter; and, the first end of the second pipe connected to the axial fan, so that operation of the fan causes airflow through the first and second pipes.
 2. The ventilation system of claim 1, further comprising a first mounting means for connecting the first pipe to the axial fan.
 3. The ventilation system of claim 1, further comprising a second mounting means for connecting the second pipe to the axial fan.
 4. The ventilation system of claim 1 where the minor and major diameters of the first pipe are sized to fit the inside diameters of standard ventilation ducts.
 5. The ventilation system of claim 1 where the minor and major diameters of the second pipe are sized to fit the inside diameters of standard ventilation ducts.
 6. The ventilation system of claim 1 where the axial fan is driven by a brushless motor.
 7. A ventilation system comprising: a first pipe; the first pipe having a first end and a second end; the first end of the first pipe having a major diameter and the second end of the first pipe having a minor diameter; the major and minor diameters of the first pipe being sized to fit the inside diameters of standard ventilation ducts; an axial fan; the axial fan driven by a brushless motor; a first mounting means connecting the first end of the first pipe to the axial fan; the first mounting means further comprising a flange integral with the first pipe; a second pipe; the second pipe having a first end and a second end; the first end of the second pipe having a major diameter and the second end of the second pipe having a minor diameter; the major and minor diameters of the second pipe being sized to fit the inside diameters of standard ventilation ducts; and, a second mounting means connecting the first end of the second pipe to the axial fan; the second mounting means further comprising a flange integral with the second pipe, so that operation of the fan causes airflow through the first and second pipes.
 8. A kit for ventilating an enclosure comprising: an axial fan; a first pipe, the first pipe having a first and second ends; the first end of the first pipe having a major diameter and the second end of the first pipe having a minor diameter; a second pipe; the second pipe having a first and second ends; the first end of the second pipe having a major diameter and the second end of the first pipe having a minor diameter; so that the kit may be assembled by connecting the first and second pipes to the axial fan to direct the airflow from the axial fan through the first and second pipes in either of two predetermined directions.
 9. The kit for ventilating an enclosure of claim 8 further comprising first and second mounting means for mounting the first end of the first pipe and the first end of the second pipe to the axial fan.
 10. The kit for ventilating an enclosure of claim 8 where the minor and major diameters of the first and second pipes being sized to fit the inside diameters of standard ventilation ducts.
 11. The kit for ventilating an enclosure of claim 8 further comprising an axial fan having a brushless motor.
 12. A kit for ventilating an enclosure comprising: an axial fan; the axial fan having a brushless motor; a first pipe, the first pipe having first and second ends; the first end of the first pipe having a major diameter and the second end of the first pipe having a minor diameter; the major and minor diameters of the first pipe being sized to fit the inside diameters of standard ventilation ducts; a second pipe; the second pipe having first and second ends; the first end of the second pipe having a major diameter and the second end of the first pipe having a minor diameter; the major and minor diameters of the second pipe being sized to fit the inside diameters of standard ventilation ducts; a first mounting means for connecting the first end of the first pipe to the axial fan; the first mounting means further comprising a flange integral with the first pipe; and, a second mounting means for connecting the first end of the second pipe to the axial fan; the second mounting means further comprising a flange integral with the second pipe, so that the kit may be assembled by connecting the first and second pipes to the axial fan to direct the airflow from the axial fan through the first and second pipes in either of two predetermined directions. 